posted on 2024-02-24, 02:14authored byRana Tanos, Hajer Tlili, Yoann Curé, Matteo Finazzer, Alberto Artioli, Saptarshi Kotal, Yann Genuist, Pierre Verlot, Joël Bleuse, Jean-Michel Gérard, Julien Claudon
Hybrid nanomechanical systems embedding a quantum light
emitter,
such as a semiconductor quantum dot (QD), are actively investigated
both for their fundamental interest and for potential applications
to quantum information technologies. Here, we explore the high-order
vibration modes of a conical GaAs nanowire that embeds a few self-assembled
InAs QDs. On-chip electrodes generate a 3D force field that can drive
flexural and longitudinal vibration modes. Mechanical vibrations are
detected optically by measuring the microphotoluminescence spectrum
of the QDs. The latter also provides a fingerprint of the mode nature.
Starting from the sub-MHz fundamental flexural mode, we show that
higher-order resonances enable a dramatic increase in both mechanical
frequency and hybrid coupling strength. In particular, we identify
a low-loss flexural mode that resonates at 190 MHz. This frequency
exceeds the QD radiative rate, which constitutes an important step
toward the resolved-sideband regime. For a QD located at the stress
maximum, the hybrid coupling strength reaches 3.9 MHz, the highest
value reported so far for a QD hybrid system. These results demonstrate
the potential of the QD-nanowire platform for high-frequency hybrid
nanomechanics.